A fan was stabbed Wednesday in Boston during the Boston Celtics' game against the Memphis Grizzlies. Photo: Reuters/Mark L. Baer-USA Today Sports

The Boston Celtics’ game against the Memphis Grizzlies on Wednesday night, at the TD Garden in Boston, turned violent when a man was stabbed during an altercation in the arena’s upper deck, according to several reports. The incident purportedly occurred near the end of the game, which was not interrupted.

A video of the fight depicted a man in a white Celtics jersey engaged in a heated argument with a man in a dark-colored Rajon Rondo jersey. [Rondo is a former Celtic who was traded to the Dallas Mavericks in December.] As the altercation escalated, the man in the white jersey appears to pull a knife out of his pocket and gesture toward the other man. A brawl broke out in the section, though it’s not clear what prompted it. Deadspin obtained footage of the brawl, which can be viewed here.

“I can confirm there was an altercation and a person was transferred” to a local hospital, TD Garden spokeswoman Tracia McCorkle told the Boston Globe. The man’s injuries were not life-threatening. Boston police responded to the scene of the stabbing shortly before 10 p.m. EDT, spokesman David Estrada said. Authorities continue to investigate the stabbing and are searching for a suspect, but have yet to make any arrests in connection with the altercation, according to WFXT television in Boston.

The tipster who submitted video of the brawl also described the scene. A fight escalated after the man in the Rondo jersey threw something at another fan, the anonymous tipster wrote to Deadspin.

“The place is going wild, so no one really notices the escalation. Then the dude pulls out a knife. You can hear the knife in the video. At the same [time] other dudes start fighting each other and even at one point a girl is punching someone in the head. People are tumbling down the stairs,” the tipster wrote.